A five hour evening climb to the summit of Stromboli volcano in Italy, reaching the active crater just before midnight and witnessing the erupting volcano live, spewing lava just a few hundreds of meters away from where she stood. That stunning moment was when Weiran (Alex) Li knew she wanted to pursue a PhD to explore the mystery of volcanoes. The trip to Italy was organized by the 2013 Goldschmidt annual conference on geochemistry, which she attended right after the first year of her master studies.
After completing her undergraduate and master’s degrees in geochemistry, and geochronology at Peking University (China), Alex moved to Singapore in 2014 to pursue a PhD with EOS–IGS under the supervision of Assoc Prof Fidel Costa. In November 2019, after gaining experience, advanced skills, and pushing the frontier of her field a bit further ahead, she successfully defended her thesis, titled Eruptive styles of volcanoes: investigation of magmatic volatile budgets and ascent rates using apatite. We caught up with Dr Li, now an EOS research fellow, to ask about her experience of doing a PhD and her research on volcanic eruptions.
You are a geochemist. What does a geochemist do?
As a geochemist and also a petrologist, I use chemical theories and techniques, combined with observation and analyses of minerals and rocks, to investigate why and how volcanoes erupted.
What is your research field and its applications?
My research interests lie in understanding the mechanisms of volcanic eruptions through chemical analyses of minerals and rocks, thermodynamic models, and experiments. I have been developing new mineral-based tools for constraining the architecture of volcanic plumbing systems, the magmatic volatile budgets, and timescales of pre-eruptive magma processes. The applications of my research involve contributing to better assessments of volcanic hazards and more accurate eruption forecasting. The more we know about a volcano, the more accurate the eruption forecasting. In SE Asia there are several active volcanoes that are located in or near densely populated areas, posing potential threats to the local communities, something that I want to be a part of changing.
Was it an obvious choice for you go for a career in science?
Yes, I plan to pursue a career in academia, as I am interested in both research and teaching. While it is important to seek for potential answers to scientific questions, I think it is also necessary to educate the public on volcanoes and other geohazards, because on this dynamic earth, these hazards are not that far from us, and we should be prepared.
How was your PhD defense?
The audience for my PhD defense included colleagues and students not only from our volcanology group, but also from other research teams at EOS/ASE. I felt quite comfortable during my 45-minute presentation, as the contents had become so familiar to me after 5 years of research. To me, the defense is an official “examination”, and more importantly, it is a good opportunity to share my research and knowledge with colleagues in EOS/ASE. It was also an opportunity to acknowledge my PhD advisor (Fidel Costa), co-advisor (Tim White), mentor (Emma Hill), and other colleagues and friends for invaluable support, advice, and encouragement. Without them it would not have been possible for me to accomplish this PhD.
PhD defense committee. Photo taken after PhD defense on Nov 8, 2019. Left to right: A/P Emma Hill, A/P Fidel Costa, Dr Alex Li, Prof Tim White, A/P Richard Webster, A/P Wang Xianfeng.
What are the most important things you have learnt from your PhD days?
I think the experience of PhD study has taught me way more things than Master study did. The two most important things that I have learnt is time management, and always make sure you know what you I want to achieve and take action to make it happen. During my PhD studies, I needed to manage several projects, such as laboratory work, coding etc., and at the same time take courses, assist with teaching, and attend conferences overseas. We had to manage our time efficiently and prioritize our tasks. It is also important to set short-term and long-term goals, and once the goals are clear, to take action as early as possible, instead of just thinking about it. For example, most PhD students I know, including myself, found that it took longer time to write the thesis than expected – knowing the results in mind, and writing them down as a scientific paper or thesis, are two different things. All in all, something to bear in mind is that no matter what challenges you encounter during your PhD days, if you manage to overcome them, this experience eventually becomes a gift to yourself.
Could you explain in layman terms what studying silicates and apatite can tell us about a volcano?
Apatite is a phosphate mineral that commonly exists in all types of rocks on Earth, and also in lunar rocks and Martian meteorites. Apatite observed in volcanic rocks were formed by apatite crystallisation from the melt within/beneath the volcano edifice (up to as deep as the mantle), followed by magma movement towards the Earth’s surface, and the consequent eruption. An interesting feature of apatite is that it can incorporate multiple magmatic volatile elements (including Hydrogen, Carbon, Sulphur, Fluorine, Chlorine etc.) into its crystal structure. Therefore, by studying volatile elements in apatite we have been able to infer volatile compositions of magmas before eruption, i.e. either stored at magma reservoirs or on their way to the earth’s surface. By using apatite to track the variation in magmatic volatile concentrations with time and space, we can evaluate the influence of magmatic volatiles on magmatic processes and eruption activities at a variety of volcanoes around the world.
Alex loading a sample into a scanning electron microscope (SEM), used for investigating the texture and chemical compositions of volcanic rocks and minerals.
The sample: An anorthoclase megacrystal from Mt. Erebus (Antarctica).
Do you collect data from the field (would be pretty dangerous in this case?) or do you work with lab experiments and/or data modeling?
My research involves field work that allows us to seek “fresh” volcanic rocks that do not seem to have had significant alteration from the environment, and thus can provide us with reliable information of the magmas from which they were formed. My field work is not very dangerous, as it is usually done after the eruption (when activity at the volcano has already calmed down). Aside from field work, my research relies extensively on chemical analyses and experiments in laboratories, as well as data processing and numerical modelling.
Do you have a favourite volcano?
My favourite volcano for now is Mount Merapi in Central Java, Indonesia, which is the main research area of my PhD study. Merapi is a very active volcano – it has erupted almost every 4 years in the past century. Most eruptions at Merapi from the beginning of the 20th century until now were small and effusive, but in 2010 Merapi erupted much more explosively and produced a “100-year” event, which severely impacted the local community located only tens of kilometres away from a highly populated city – Yogyakarta. My PhD work mainly focused on investigating the cause of the effusive-explosive transition at Merapi, by comparing the magmatic volatile budgets and ascent rates of the effusive event in 2006 and the more explosive one in 2010. Hopefully, with the petrological and experimental work from my PhD and previous work by many other researchers, as well as a better monitoring system to be set up at Merapi, eruptions at this volcano can be better anticipated in the future.
The main research area of Alex’s PhD : Mount Merapi in Central Java, Indonesia, one of the world’s most active volcanoes, located near a densely populated city – Yogyakarta.
You now work as a research fellow with EOS. What do you see yourself doing in 10 years’ time and where?
I hope at that time I will be a professor at some Chinese university, as I would like to help to promote the research and education related to volcanology in China, where there is still some room for improvement.
Do you have any advice for prospective or new PhD students?
Stay positive, and you can do it!